1) Ovine oligodendrocytes (OOG) are being purified from sheep brain daily and are being maintained in culture for several weeks. We will test lymphocytes from MS patients and controls for CMI response to mitomycin blocked OOG measuring tritiated thymidine uptake as well as cytotoxicity measuring 51Cr release from labelled OOG. Anti-OOG antibodies in MS sera and CSF will be studied by indirect fluorescence and by adsorption from CSF to assess removal of oligocclonal IgG bands. Receptors for acetylcholine and other transmitters will be sought on cultured OOG. Attempts to differentiate OOG in vitro with maturation factors (cAMP, prostaglandins, serum deprivation) and to stimulate proliferation with axolemmal preparations will be made. 2) Suppressor cells (S cells) - Assays of S cell activity in MS, MG, ALS and other neurologic diseases will be continued. 3) Cytofluorometry - Evaluation of CSF cells will be continued. 4) HLA typing of patients with neurologic disease will be pursued. 5) CMI to elective organ AChR in MG and other neurologic diseases will continued to be assayed.